Emscripten resize doesn't work with SDL_SetWindowResizable()

[esotericpig]

I'm using SDL2 and found quite a strange bug.

I set up my window like this for my desktop app:

window = SDL_CreateWindow(
  title_.c_str(),SDL_WINDOWPOS_CENTERED,SDL_WINDOWPOS_CENTERED,config.size.w,config.size.h,
  SDL_WINDOW_OPENGL | SDL_WINDOW_ALLOW_HIGHDPI
);

// The SDL_WINDOW_RESIZABLE flag in SDL_CreateWindow() increases the size for some reason
// (even w/o SDL_WINDOW_ALLOW_HIGHDPI), but this explicit call doesn't.
SDL_SetWindowResizable(window,SDL_TRUE);

This was to fix a bug already for my system. For some reason, if I added | SDL_WINDOW_RESIZABLE, it would increase my requested window size from 1600x900 to something slightly bigger. This is on Linux.

Anyway, I ported my game to Emscripten, using the same code. I handle SDL2 resize events. However, whenever I would resize the browser window, I wouldn't receive any window resize events. Finally, after racking my brain over it and trying different things, I finally went to the code at SDL_emscriptenevents.c#Emscripten_HandleResize(). I saw the line window_data->window->flags & SDL_WINDOW_RESIZABLE, and decided to add that to SDL_CreateWindow(), even though SDL_SetWindowResizable() should already add it.

And voila, it works!

So I basically have to do this:

#if defined(__EMSCRIPTEN__)

  window = SDL_CreateWindow(
    title_.c_str(),SDL_WINDOWPOS_CENTERED,SDL_WINDOWPOS_CENTERED,config.size.w,config.size.h,
    SDL_WINDOW_OPENGL | SDL_WINDOW_ALLOW_HIGHDPI | SDL_WINDOW_RESIZABLE
  );

#else

  window = SDL_CreateWindow(
    title_.c_str(),SDL_WINDOWPOS_CENTERED,SDL_WINDOWPOS_CENTERED,config.size.w,config.size.h,
    SDL_WINDOW_OPENGL | SDL_WINDOW_ALLOW_HIGHDPI
  );

  SDL_SetWindowResizable(window,SDL_TRUE);

#endif

It seems as though SDL_SetWindowResizable() doesn't work with Emscripten for some reason.

[slouken]

I believe this is fixed in SDL3, can you try that?

[esotericpig]

I tested with SDL3 today. In Emscripten, it has the same bug. SDL_SetWindowResizable() doesn't work, and you must include SDL_WINDOW_RESIZABLE as part of the flags in SDL_CreateWindow() instead.

[slouken]

Okay, I believe we are reworking emscripten resizing for SDL 3.4.0.